Method of delustering fabric



Patented Dec. 15, 1936 UNITED STATES PATENT OFFICE METHOD OF DELUSTERINGFABRIC ware No Drawing. Application September 1, 1928, Serial No.303,602

4 Claims.

This invention relates to the treatment of textile materials containingorganic derivatives of cellulose so as to subdue the luster of the same.

An object of our invention is to reduce the luster of textile materialscontaining organic derivatives of cellulose in such a manner that thedeluster effect is comparatively permanent.

Another object ofour invention is to deluster textile materialscontaining organic derivatives of cellulose by precipitating an opaqueand insoluble salt in the textile material. Qther ob jects of ourinvention will appear from the following detailed description.

Heretofore textile materials containing organic derivatives ofcellulose, such as cellulose acetate, have been delustered by boilingwater, wet steam or aqueous solutions of various reagents. ever, thedelustering effect produced by such processes is not permanent and suchdelustered fabrics regain all or part of their luster when they areironed while damp or subjected to dry steam or other agencies. ency toreluster is a serious drawback.

We have found that a practically permanent subdued luster may beimparted to an organic derivative of cellulose material by precipitatingan opaque insoluble salt throughout and within the fibres of the yarn ofthe organic ester of cellulose.

In accordance with our invention, we treat, a textile materialcontaining organic derivatives of cellulose with a solution of a salt ofa metal that produces a white and opaque salt, which is itself aswelling agent for the organic derivatives of cellulose, or in thepresence of a foreign swelling agent, and then treat the same with asolution that is adapted to precipitate the metal in the form of anopaque and white salt.

The textfle material to be treated in accordance with our invention maybe in the form of yarns in a suitable package such as in hanks, onbobbins, etc. However, we prefer to treat a fabric containing yarns ofsuch organic derivatives of cellulose. The fabric may contain anyorganic derivatives of cellulose such as cellulose esters and celluloseethers. Examples of cellulose esters are cellulose acetate, celluloseformate, cellulose propionate and cellulose butyrate, while examples ofcellulose ethers are ethyl cellulose, methyl cellulose and benzycellulose. The fabric need not consist wholly of yarns of such organicderivatives but may also contain yarns of other material such as cotton,silk, wool, etc.

HOW-

Obviously this tend- We have found that solutions of salts of thealkaline earth metals such as barium, calcium or strontium producesatisfactory results. The solutions of such salts may be of themselvesswelling agents. Examples of such salts are the sulfocyanides of bariumor other alkaline earth metal. On the other, hand, salts of such metalssuch as the chloride or chlorate of barium may be employed, which ofthemselves are not swelling agents. In this case the treat- 10 ing bathmay also contain a swelling agent such as formic acid, acetic acid,acetone, etc. If desired, the textile material may be first treated witha bath containing these swelling agents and then with a bath containingthe salts of the 15 alkaline earth metals.

'After treatment with the solutions of the alkaline earth metals, thetextile material is then treated with a solution that is adapted toprecipitate the metal in the form of an 20 opaque and white salt.Suitable reagents for this purpose are aqueous solutions of sulphuricacid, phosphoric acid or the soluble salts of these acids such as thesulphates or phosphates of sodium, potassium, or ammonium. By treating dof the material in such baths, the sulphates or phosphatesv of barium,strontium or calcium are formed.

Because of the action of the swelling agent, the salts permeatethroughout the fibres and are generally retained therein so that whenthey are precipitated as insoluble salts they will not wash out. Thetextile materials produced by our invention have a subdued lustervarying from complete deluster to partial deluster depending on theconcentration and time of treatment, and this deluster effect ispermanent. Fabrics when treated by our invention may be ironed whiledamp or subjected to dry'steam or other relustering agent withoutbecoming relustered.

To obtain further desirable effects, the textile material to be treatedby our invention may be partially saponified and particularly intenselysurface saponified. By this is meant. treat-' ment with alkalinesolutions in such concentrations and in such manner that only the outerlayers of the fibres of cellulose ester material isysaponified, whilethe inner core is preferably unaffected so that the safe ironing pointis ma.- terially increased. This partial saponification stepmay becarried out on the textile material either prior to the delusteringtreatment or subsequent thereto.

The fabrics when treated in accordance with our invention have anafiinity for organic derivatives of cellulose dyestuffs and basicdyestuffs, and also have an increased aifinity for direct cotton colorsand for acid colors.

In order further to illustrate our invention, the following specificexamples are given.

Example I A fabric consisting solely of yarns of cellulose acetate istreated for one hour at 70 C. in a 25 'Ifw. solution of bariumthiocyanate. It is then treated for 20 minutes in the cold in a 1%solution of sulphuric acid, after which it is rinsed and dried. Thefabric so treated is quite well delustered, which luster is notappreciably affected by ironing or washing.

Example II A fabric consisting wholly of cellulose acetate is firsttreated for one hour at 50 C. in an aqueous solution containing 20% offormic acid, which acts as a swelling agent. It is then treated for onehour at 70 C. in a solution of barium chloride and is then treated for20 minutes in the cold in a 1% aqueous solution of phosphoric acid andis then rinsed and dried. The fabric is satisfactory delustered and isnot appreciably relustered by ironing, either wet or dry or by washing.

The fabric resulting from the treatments of the foregoing examplescontains filaments wherein the barium compound, which is a pigment-likeinorganic material, occurs as small particles subnierged in and widelydistributed throughout the mass of the filaments and the quantity anddistribution of the particles is such as not to materially impair thecontinuity of the mass of the filaments. Moreover the amount of bariumcompound that becomes incorporated in the filaments is a smallpercentage of the mass of the filaments. Such barium compounds are inertto the action of chemicals used in the manufacture, dyeing and bleachingof the filaments or fabrics.

We are well aware of the fact that textile materials containing organicderivatives of cellulose, such as cellulose acetate, have beenpreviously treated with salts of tin and the like for the purpose ofweighting the same. Our invention is quite different from this weightingprocess, since the materials used for weighting are employed for adifferent purpose and therefore the weighted material has substantiallythe same luster as the original material, while the weight of the sameis materially increased, whereas in our process the luster of thetextile material is substantially subdued and the weight thereof is butslightly increased.

It is to be understood that the foregoing detailed description is givenmerely by way of illustration and that many variations may be madetherein without departing from the spirit of this invention.

Having described our invention what we claim and desire to secure byLetters Patent is:

1. Method of treating fabric containing yarns of organic derivatives ofcellulose comprising treating such fabric with a solution of bariumsulphocyanide and then treating the fabric with a solution containingsulphate ions, whereby barium sulphate is precipitated within the fibresof such yarn.

2. Method of treating fabric containing yarns of cellulose acetatecomprising treating such fabric with a solution of barium sulphocyanideand then treating the fabric with a solution containing sulphate ions,whereby barium sulphate is precipitated within the fibres of such yarn.

3. Method of treating fabric containing yarns of organic derivatives ofcellulose comprising treating such fabric with a solution of an alkalineearth metal sulphocyanide which is a swelling agent for the derivativeof cellulose and then treating the fabric with a solution containingions selected from the group consisting of sulphate and phosphate ions,whereby an insoluble alkaline earth metal compound is precipitatedwithin the fibres of such yarn.

4. Method of treating fabric containing yarns of cellulose acetatecomprising treating such fabric with a solution of an alkaline earthmetal sulphocyanide which is a swelling agent for the cellulose acetateand then treating the fabric with a solution containing ions selectedfrom the group consisting of sulphate and phosphate ions, where-

